Portable belt conveyor

ABSTRACT

Portable belt conveyor for use in a mining conveyor system to carry coal or ore away from a mine face. It provides an essential link in a train of conveyors where it is located between highly mobile conveyors which move from face to face with a mining machine, and an extendable output conveyor. In a typical mining application it is 100 to 200 feet long and includes a series of intermediate frame sections between head and tail end sections. Each section is individually rigid and includes a pair of spaced parallel side rails with upper tracks for rollingly supporting the discharge carriage of a bridge conveyor. Each side rail has a longitudinal extension consisting of a vertical plate at each end. The plates of adjacent sections are lapped in side-by-side relation and pivoted for relative up and down movement. Each plate has an upper arcuate surface concentric with its pivot and tangent with the track surface, thereby providing continuous and gap-free support for the bridge conveyor carriage between sections regardless of the degree of up or down articulation. A conveyor belt, trained between reversing pulleys in the head and tail end sections, is supported in upper, load-carrying and lower, return runs in the intermediate frame sections. Skids on the sections, and a swivel jack on the head end section, enable the conveyor to be advanced, retreated, and swung as a unit without horizontally distorting the frame and detraining the belt. A spring-biased compensating roller in the head end section minimizes fluctuations in belt tension due to changes in the degree of articulation between sections.

United States Patent 1 Nelson [4 1 Oct. 2, 1973 PORTABLE BELT CONVEYOR [75] Inventor: Robert C. Nelson, Blueficld, W. Va.

[73] Assignee: West Virginia Armature Company, Bluefield, W. Va.

221 Filed: Feb. 28, 1972 21 Appl. No.: 229,979

[52] U.S. Cl 198/117, 198/109, 238/10 [51] Int. Cl. B6Sg 21/00 [58] Field of Search 198/117, 109, 139; 299/18; 238/10 R [56] References Cited UNITED STATES PATENTS 1,817,348 8/1931 Claghorn [98/109 3,343,650 9/1967 'Brown 198/117 3,268,060 8/1966 Long 198/139 2,722,409 11/1955 Bergmann. 198/109 2,850,146 9/1958 Madeira 198/109 2,851,150 9/1958 Boersma ..198/109 3,348,663 10/1967 Schmieder 198/192 Primary Examiner-Richard E. Aegerter Attorney-James A. Davis et al.

[5 7] ABSTRACT Portable belt conveyor for use in a mining conveyor system to carry coal or ore away from a mine face. It

provides an essential link in a train of conveyors where it is located between highly mobile conveyors which move from face to face with a mining machine, and an extendable output conveyor. In a typical mining application it is 100 to 200 feet long and includes a series of intermediate frame sections between head and tail end sections. Each section is individually rigid and includes a pair of spaced parallel side rails with upper tracks for rollingly supporting the discharge carriage of a bridge conveyor. Each side rail has a longitudinal extension consisting of a vertical plate at each end. The plates of adjacent sections are lapped in side-by-side relation and pivoted for relative up and down movement. Each plate has an upper arcuate surface concentric with its pivot and tangent with the track surface, thereby providing continuous and gap-free support for the bridge conveyor carriage between sections regardless of the degree of up or down articulation. A conveyor belt, trained between reversing pulleys in the head and tail end sections, is supported in upper, load-carrying and lower, return runs in the intermediate frame sections. Skids on the sections, and a swiveljack on the head end section, enable the conveyor to be advanced, retreated, and swung as a unit without horizontally distorting the frame and detraining the belt. A spring-biased compensating roller in the head end section minimizes fluctuations in belt tension due to changes in the degree of articulation between sections.

11 Claims, 17 Drawing'Figures Pmtminw'w 3.762.532

SHEU 10E 1 PATENIEUIm 2m SHEET 3 [IF 7 PORTABLE BELT CONVEYOR BACKGROUND OF THE INVENTION The field of the invention is generally that of belt conveyors.

In a typical underground coal mining system where the present invention can be used to advantage, three or more parallel rooms may be driven up simultaneously. A mining machine such as a continuous miner or loader advances the mine face in each room in turn, constantly flitting from room to room. A bridge conveyor has its receiving end pivoted beneath the discharge end of the mining machine and has a wheeled carriage at its discharge end rollingly supported along tracks on a mobile transfer conveyor or carrier, the latter being a short conveyor carried on running gear to make it maneuverable under its own power. The bridge conveyor carriage discharges at any position along the mobile transfer conveyor depending on the extent of telescopic overlap. A second bridge conveyor has its receiving end pivoted beneath the discharge end of the mobile transfer conveyor and has a wheeled carriage at its discharge end rolling along tracks on a movable floor conveyor and discharges at any position along it depending on the extent of telescopic overlap. The movable floor conveyor discharges onto an extendable output conveyor which transfers the material to other equipment or conveyors to carry it out of the mine.

The telescopic overlaps and ability to operate around corners provided by the two bridge conveyors enable the rooms to be driven up substantial distances, and breakthroughs driven between rooms in different directions. When the mine faces are advanced sufficiently to use up the overlaps, the system will be reset fora new advance by winching the movable floor conveyor in an inbye direction (that is, toward the faces), and the output conveyor will be extended correspondingly.

The system is equally effective in retreat to extract pillars between the rooms in which case the system will be reset from.time to time by winching the movable floor conveyor-in an outbye direction. (away from the faces) and the output conveyor will be shortened correspondingly. v c I I The movable floor conveyor" referred to above is an important application of this invention.

Movable floor conveyors for such use originally were chain conveyors, a naturaIapplication using the up with uneven floor, and still provide a pair of smooth,

continuous, gap-free tracks to accommodate easy back andforth movement of the bridge conveyor carriage.

SUMMARY OF THE INVENTION A general object of the invention is to provide a portable beltconveyorhaving the following advantages when used with a bridge conveyor discharging onto it:

a. the individual frame sections are freely vertically articulated, providing a high degree of compliance with uneven floor;

b. the belt tension level remains substantially uniform regardless of changes in the degree of articulation of the supporting frame assembly;

c. the supporting frame assembly is horizontally rigid to keep the conveyor belt in train;

d. it is readily movable as a unit in inbye and outbye directions to follow an advancing or retreating mining operation;

. the head section is swiveled to a jack, enabling the conveyor to swing about the jack as a unit without distortion when subjected to side thrusts by the bridge conveyor or other mining equipment, also enabling the conveyor to be swung intentionally where desired to clear other face equipment while maintaining the head discharge centered over'the extendable output conveyor; and

f. it includes a pair of parallel, continuous tracks which are gap-free at the joints between frame sections at all upwardly and downwardly articulated conditions, for smoothly supporting a longitudinally movable bridge conveyor carriage at the joints.

An important feature is that, although the end and intermediate frame sections are vertically pivotally interconnected, they are individually rigid thereby preventing horizontal racking or distortion by side forces.

Another important feature is that the frame sections have spaced horizontal side rails held in rigidly fixed parallel relation, each having an upper track surface.

' the following continuous side guide surfaces to maintain the carriage of a bridge conveyor centered on the side rails during movement along the frame sections. 1

Another important feature is a roller which is springbiased against the return run of the belt in the head end section to minimize fluctuations in belt tension caused by variation in the spacing between the reversing pulleys when changing floor condition causes a change in the degree of articulation of the sections.

Another feature is the provision of a swivel jack at the head end section providing a single point pivoted anchor to keep the head end section centered over the.

output conveyor.

Otherobjectsand advantages will be apparent from description, taken in connection with the drawings in which:

FIG.'1 is a top plan view in solid lines of a portable belt conveyor embodying the present invention, being shown with other elements in broken lines illustrating an overall conveying system for moving coal away from a set of mine faces being driven up together;

FIG. 2 is an enlarged fragmentary view of FIG. 1

showing the head end (discharge) section FIG. 2A is a side view of FIG. 2 and is an enlarged fragmentary side view of FIG. I seen in the direction of arrow 2A'2A;

FIG. 3 is an enlarged fragmentary view of FIG. 1 showing the tail end (receiving) section;

FIG. 3A is a side view of FIG. 3 and is an enlarged fragmentary side view of FIG. I seen in the direction of arrows 3A3A;

FIG. 4 is an enlarged cross-sectional view of FIG. 3 taken along line 44;

FIG. 5 is a side view of FIG. 4 as seen in the direction of arrows 5-5;

FIG. 6 is a longitudinal cross-sectional view of FIG. 4 taken along line 66, without belt;

FIG. 7 is a horizontal sectional view of FIG. 6 taken along line 77;

FIG. 8 is an enlarged fragmentary view of one of the vertically pivotal connections between adjacent side rails showing the smooth, continuous, gap-free supporting track for supporting a bridge conveyor carriage;

FIG. 9 is similar to FIG. 8 with the major components shown unassembled;

FIG. 10 is an enlarged fragmentary view of FIG. ZA showing the belt compensating means in the head end section;

FIG. 11 is a vertical cross-sectional view of FIG. 10 taken along line 11-11;

FIGS. 12 and 13 are diagramatic views showing the compensating apparatus of FIGS. 10 and 11 when the conveyor is on level floor in one case and uneven floor in the other case;

FIG. 14 is a fragmentary view of the pivotal joint between adjacent frame sections, similar to a portion of FIG. 6 but showing the joint articulated upward in an exaggerated degree; and

FIG. 15 is a perspective view of an intermediate frame section, with the conveyor belt and troughing roller assemblies omitted.

Like parts are designated by like reference characters throughout the figures in the drawings.

FIG. 1 illustrates a coal mining operation in which three rooms 20, 22 and 24 are driven up together and a portable belt conveyor, in accordance with the present invention, is part of a train of conveyors which transport mined coal away from a face as fast as it is produced.

In FIG. 1 a continuous miner A is shown at face 26 of room 20. Alternatively, A may be a loading machine which follows a continuous miner or follows a conventional cutting and shooting operation. Coal produced at the face is transported outbye, continuously as produced, by a train of cascade conveyors including a first bridge conveyor B, a mobile transfer carrier C, a second bridge conveyor D, a portable belt conveyor E, and an extensible output conveyor F which discharges into other conveyors or mine cars (not shown) for transport to the outside.

The first bridge conveyor B has its receiving end 28 pivotally mounted beneath the discharge end of mining machine conveyor 30. The discharge end of the first bridge conveyor is mounted on a wheeled carriage or dolly 32 which moved back and forth on tracks 34, 34 of the carrier C.

The carrier C is self-propelled on running gear shown here as a pair of endless crawlers 36, 36. A central conveyor. between tracks 34, receives the discharge from bridge conveyor B at any position along its length depending on the degree of telescopic overlap between B and C.

The second bridge conveyor D is essentially a counterpart of B, having a receiving end 38 pivotally mounted beneath the discharge end of mobile transfer carrier C. A wheeled carriage or dolly 40 at the discharge end runs back and forth along side rails 42, 42 of the portable belt conveyor E.

Output conveyor F may be of any type which is readily extensible as room advance requires additional conveyor length.

Briefly, the system shown in FIG. 1 operates as follows: the mining machine A flits from place to place as required to drive up the rooms 20, 22 and 24 and the transverse breakthroughs 44, 46, etc. Two different positions for components A, B, C and D are shown. In beginning an advance, bridge conveyors B and D will be telescoped substantially toward the discharge ends of the mobile transfer carrier C and the portable belt conveyor B, respectively. As the rooms are advanced, this telescopic overlap will decrease until the bridge conveyor carriages 32 and 40 are near the receiving ends ofC and E, as shown in FIG. 1. At that time, in preparation for a new advance, the portable belt conveyor B will be winched forward (by means not shown), skidding it across the mine floor, and the output conveyor F will be extended appropriately to maintain it in receiving relation with conveyor E. Mining will then be resumed starting from a new position of substantial overlap between conveyors B and C, and D and E.

The portable belt conveyor E of the present invention, which is shown only generally in FIG. 1, is shown in detail in the following drawings. It will now be described.

The portable belt conveyor E comprises a head end section 48, a tail end section 50 and a series of intermediate frame sections 88.

The head end section is best shown in FIGS. 2 and 2A. It comprises a pair of vertical side plates 54, 54 held in fixed spaced relationship by transverse braces 56. Ground engaging skids 58 and 60 have upturned end portions 62 to facilitate sliding along a mine bottom. A space therebetween facilitates clean-up under the return run of the belt. Troughing roller assemblies 64 are mounted between the side plates 54 and may be identical with those in the intermediate frame sections 88, to be described. A hold-down roller 65 for a conveyor belt return run is journaled between the side plates 54.

The head end section has journaled therein a belt reversing pulley 66 driven by motor 68 through reducer 70, chain 72 and sprockets 74 and 76. An idler roller 78 is positioned to improve the belt wrap and the driving tension of pulley 66.

FIGS. 3 and 3A show the tail end section 50. This comprises a pair of hollow rectangular cross-section side rails 42 which may be identical with those in the intermediate frame sections 88. They are held in fixed spaced relationship by transverse bracing elements including a belt slide shoe 80 and an end yoke 82. The shoe 80 has an upper curved guide surface which slidingly supports the return run of the belt. TI-Ie yoke 82 has an aperture 84 providing a convenient grip for a hook or cable used from time-to-time to drag the conveyor along the bottom. A reversing pulley 86 is journaled between the side rails 42 in the tail end section to support the receiving end of the belt.

Between the head and tail end sections, the intermediate frame sections 88 are arranged end to end along a straight conveying course. One of these intermediate frame sections, with troughing roller supports removed, is shown in FIG. 15.

Each frame section includes a pair of elongated side rails 42 maintained in rigid, horizontally spaced relation parallel to the conveying course by transverse struts 90 fastened as by welding to the side rails. They are ground-supported by skids 92 having upturned diagonal ends; these may be identical counterparts of the skids on the tail end section 50.

As best shown in FIG. 4, each side rail 42 comprises a rectangular cross-section, hollow, box-channel member having side walls 94 and 96, and top and bottom walls 98 and 100. The skids 92 are substantially the same width as the bottom walls and are fastened thereto as by welding. The top surface 102 of each channel top wall 98 comprises a track to rollingly support the wheels 104 of the second bridge conveyor carriage 40. (See FIGS. 3A and 8.)

The intermediate frame sections 88 are connected to one another and to the head and tail end sections by pivotal means which will now be described.

Refer to FIGS. 8 and 9. At one end each rail 42 is formed with upper and lower central, longitudinal, open-ended slots 104. A vertical plate 106 is assembled in the slots and held in place as by welding. Each plate 106 has a pivot opening 108 with a tubular bushing 110, and a horizontal top surface 112, coplanar with the track surface 102 and an arcuate extended surface 114 concentric with the pivot opening 108 and tangent to the track surfaces 112 and 102.

At the opposite end of each rail 42, rectangular openings 116 are provided in each side wall 94 and 96, leaving longitudinal extensions 118 and 120 of the top and bottom walls 98 and 100. A pair of vertical side plates 122, 122 are assembled within the openings 116 and spaced just far enough apart to flank and closely lap opposite sides of plate 106.

Each plate 122 has an inner end portion of sufficient vertical dimension to fit snugly between-the upper and lower wall extensions 118,120, with their outer surfaces substantially flush with theouter surfaces of the side walls 94, 96. Plates 122- are fixed in place, as by welding. Each plate member 122 has a pair of shoulders 124 engageable with the ends of extensions 118 and 120. Each has a pivot aperture 126 with a tubular bushing 128 which may be identical with bushing 110. There is a top horizontal surface 130 on each plate 122, coplanar with top track surface 102. Each surface 130 has an arcuate extended surface 132 which is concentric with the pivot aperture 126 and is coplanar with the upper track surfaces 130 and 102. Each plate 122 has an external counterbore'134 to receive the ends of a headed pivot pin 136 which extends through the bushings 128, 110, 128 when the pivot apertures are in registration, as shown in FIG. 8. A cotterpin 138, externally of washer 135, holds each pin in place.

As best shown in FIG. 7, the outer connector plate 122 has an, outer vertical guide surface which is coplanar with the outer vertical guide surfaces'on outer side walls 94 of adjacent connected side rails. This provides a continuous outer guide for side rollers 137 of a bridge conveyor.

' The pivotal connections centered at the pins 136 enable freely pivotal vertical articulation between the sections 48, 50 and 88. The rigidity of the individual sections and the closely lapped relation between vertical connecting plates 106 and 122 provide positive horizontal rigidity to the entire conveyor, preventing racking of the side rails, and horizontal distortion, which would detrain the belt. Further, as is readily seen in FIGS. 5 8 and 14, the upper track surfaces 102, 112, 114, and 132 provide continuous, gap-free upper surfaces for smoothly supporting rollers 104 of bridge conveyor carriage 40 along the entire length of conveyor E.

Troughing roller assemblies 64 are disposed along the end and intermediate frame sections to support the upper, load carrying run 140 of a conveyor belt 142. Each includes a transverse, inverted T-bar 144 having horizontal center section 146 (FIG. 4) and inclined end sections 148, 148. Ears 150 carry a center roll 152, and ears 154, 156 carry inclined troughing rollers 158. L- shaped brackets 160 welded to T-bar 144 are held by bolts 162 to brackets 164 welded to side rails 42.

Transverse slightly downwardly bowed tube members 166 are welded at intervals to the inside walls of the side rails 42. These provide periodic supports for the return run 168 of the belt which is trained between the reversing pulleys 66 and 86 in the head and tail end sections respectively. These enhance the rigidity of the individual intermediate frame-sections 88. If desired, to improve wear resistance, slide shoes 80 (FIGS. 3 and 3A) may be used in place of the tube members 166. Alternatively, conventional return rollers (not shown) may be substituted for some or all of the members 80 and 166.

As shown in FIG. 3A, belt take-up mechanism is disposed within the hollow spaces in the side rails 42, 42. The tail pulley 86 is journaled at each end within a block 172 which is slidably mounted for movement in a space 174 between a pair of upper and lower slide tracks 176 and 178, respectively. A pair of cylinder/piston assemblies 180, 180 are mounted between the slide blocks 172 and corresponding fixed blocks 182 within the side rails.

By introducing hydraulic fluid or grease under pressure, within the two cylinder assemblies 180 simultaneously, the tail pulley 86 can be shifted in a direction to align and tension the belt toa degree suitable for the head pulley to drive it and for supporting mined material on the upper run.

One of the problems not solved by previous attempts to develop a portable belt conveyor for the purpose described herein is the variation in tension level of the belt when the up-and-down articulated condition of the frames changes from a flat floor to a highly uneven floor and vice versa. If the tension level as set by the take-up cylinder 180 is proper for a perfectly flat floor, it may be considerably reduced as the spacing between head and tail pulleys is decreased when the frame sections articulate to followan uneven bottom.

Accordingly, an important part of the present invention is the belt compensating means in the head end section as shown in FIGS. 2A and 10-13. A compensating roller l84-is positioned to engage the top side of the return belt run 168. The ends of the roller shaft 186 are carried in a bearing block 188 on the exterior of each head section side plate 54. A vertical slot 190 in each side plate enables the roller'shaft 186 to work up and down. A frame comprising vertical side plates 192 and top and bottom plates 194, 196 is fixed as by welding to the exterior of each side plate 54. Vertical guide bolts 198, 198 extend between plates 194 and 196 and pass with some working clearance through guide bores 200 in wing extensions 202 of bearing blocks 188. The compensating roller 184 is spring-biased in a downward direction against the return run by coil springs 204 which encircle the bolts 198. Operation of this mechanism is illustrated in FIGS. 12 and 13 in the overall environment of the conveyor.

FIGS. 12 and 13 are schematic views with the length of the conveyor E greatly condensed in order to show all cooperating parts in one view.

FIG. 12 shows the conveyor on a perfectly flat bottom. If the take-up cylinder assemblies 180 are adjusted under this condition, the compensating roller 184 may have a position as shown, displacing the return run 168 downward in a relatively small bight.

Subsequently, when the conveyor is moved to uneven bottom, the resultant articulation of the sections as shown in FIGS. 13 will reduce the distance between the head and tail pulleys 66 and 86. In conventional belt conveyors, this would reduce the tension in the belt and correspondingly reduce the driving friction at the head pulley. In the present invention, however, the compensating roller 184 is displaced downwardly by spring 204 to take up the slack and to minimize fluctuation of tension in the belt. This displacement is shown in FIG. 11 where the upper position of the roller 184 is shown in solid lines and the lower position is shown in broken lines. Another important feature of the invention is shown in FIGS. 2 and 2A. A swivel mounting bracket 206 is fastened as by welding to one of the side plates 54. It has a cap 208 held in place by bolts 210. The bracket and cap define a vertical cylindrical opening 212 which receives a floor-to-roof jack 214 with sufficient clearance to enable the head section to swivel about the jack. Due to the proximity of the jack to the output conveyor F, no practical amount of swiveling will mis-align the two conveyors.

In practice, the portable belt conveyor E may be held in place only by the jack 214 and the frictional engagement of the skids 58, 60 and 92 with the ground. The entire conveyor may be swung as a unit about the jack as a pivot point, when necessary to clear other equipment, while maintaining the head section centered over the output conveyor. When side forces or impacts are applied to the conveyor, either by the bridge conveyor, or other mining machinery, the swivel jack, combined with the extreme horizontal rigidity of the sections enables the conveyor to swing as a unit out of the way without racking or distorting the frame and possibly detraining the belt.

It will be understood that the horizontally rigid and vertically flexible elongated frame described may be used advantageously in a wide variety of movable belt conveyors which operate on uneven floor, and that this novel frame is not necessarily limited to use in the specific conveyor disclosed. As an example, the novel frame may be employed in the intermediate section only, in the head end section only, in the tail end section only, or in two or more of those sections.

While one form in which the present invention may be embodied has been shown and described, it will be understood that various modifications and variations thereof may be effected without departing from the spirit and scope of the invention as defined by the appended claims.

I claim:

1. In a portable belt conveyor for receiving the discharge from a bridge conveyor comprising:

head and tail end sections each having a beltreversing pulley;

belt drive means in one of said end sections;

a series of intermediate frame sections arranged endto-end along a conveying course between said end sections;

each of said intermediate frame sections including a pair of elongated side rails maintained in rigid, horizontally spaced relation parallel to said course by members extending between said side rails;

ground support members on said side rails;

each of said frame sections having upper and lower belt-supporting members extending transversely between said side rails for supporting upper and lower runs of a conveyor belt;

each of said side rails having an upper horizontal surface and having longitudinal extensions comprising vertical connector plate means at each end thereof with its upper surface extending from the rail surface with a portion thereof in substantial coplanar relation, each of said connector plate means having aperture means therein and being in side-by-side lapped engament with similar connector plate means on an adjacent section, the aperture means of the lapped connector plate means being in registration;

a horizontal pin extending through the registered aperture means in each set of lapped connector plate means to provide free vertical articulation and horizontal rigidity between adjacent sections;

each connector plate means having at least another portion of its surface of arcuate form concentric with said aperture means and tangent to the plane of said upper horizontal surface on the correspond ing side rail;

said upper horizontal and arcuate surfaces providing a pair of parallel, continuous, gap-free tracks throughout a substantial range of upwardly and downwardly articulated conditions of said sections for smoothly supporting a longitudinally movable discharge carriage of a bridge conveyor or the like.

2. In a portable belt conveyor, the combination of claim 1 in which said ground support members comprise ground-engaging skids carried by said side rails.

3. In a portable belt conveyor, the combination of claim 2 in which a groundand roof-engaging jack is swivelably supported on said head end section to enable said conveyor to swing horizontally as a unit about said jack.

4. In a portable belt conveyor, the combination of claim 1 in which each transverse pair of side rails are rigidly interconnected by transverse struts positioned between the upper and lower runs of a conveyor belt supported respectively on said upper and lower beltsupporting members.

5. In an underground mining conveying system for moving mined materials away from a mine face, a portable belt conveyor adapted to receive mined material from an inbye bridge conveyor having a discharge carriage supported for longitudinal movement along said portable belt conveyor and adapted to discharge said mined material to an outbye conveyor, said portable belt conveyor comprising:

a head section;

a tail end section;

a belt-reversing pulley in each of said end sections;

an endless belt trained between said pulleys in upper and lower runs and extending along a conveying course between said end sections;

belt drive means in one of said end sections;

a series of intermediate frame sections arranged endto-end along said course between said end sections;

each of said intermediate frame sections including a pair of elongated side rails maintained in rigid, horizontally spaced relation parallel to said course by members extending between said side rails;

ground support member on said side rails;

each of said intermediate frame sections having transverse supporting members for said upper and lower runs extending between said side rails;

each of said side rails including an upper horizontal surface and having a longitudinal extension comprising at least one vertical connector plate at each end with its upper surface extending from the rail surface with a portion thereof in substantial coplanar relation; I a I each said connector plate of each side rail being in side-by-side lapped engagement withat least one similar connecting plate on an adjacent section;

each set of lapped connector plates having registered pivot apertures with securing elements extending therethrough providing free vertical articulation and horizontal rigidity, between adjacent sections;

each said connector plate having another portion of the upper surface of arcuate form concentric with said pivot aperture thereof and tangent to the plane of said upper horizontal surface on the corresponding side rail;

said upper horizontal and arcuate surfaces providing a pair of parallel, continuous, gap-free tracks throughout a substantial range of upwardly and downwardly articulated condition of said sections for smoothly supporting a longitudinally movable discharge car-riage of a bridge conveyor or the like.

6. In a portable belt conveyor for receiving the discharge from a bridge conveyor comprising:

head and tail end sections each having a beltreversing pulley; a

belt take-up means in one of said sections including means for selectively moving the belt-reversing pulley thereinin a direction parallel to said course to selectively vary the tension level ina belt;

belt compensating means in said head end section in cluding a compensating roller engageable with the return run of a belt, means for guiding said com-- pensating roller for movement in a direction transverse to said return run, and biasing means urging said roller'rtoward said retum-run';

belt drive means in one of said sections;

a series of intermediate frame sections arranged endto-end along a course between said end sections;

each of said intermediate frame sections including a pair of elongated side rails maintained in rigid, horizontally spaced relation parallel to said course by members extending between said side rails;

ground support means on said end and intermediate sections;

each of said intermediate frame sections having upper and lower members extending transversely between said side rails for supporting upper and lower runs of a conveyor belt;

each of said side rails having an upper horizontal surface and having longitudinal extensions comprising vertical connector plate means at each end thereof with its upper surface extending from the rail surface with a portion thereof in substantial coplanar relation, each of said connector plate means having aperture means therein and being in side-by-side lapped engagement with similar connector plate means on an adjacent section, the aperture means of the lapped connector plate means being in registration;

a horizontal pivot pin extending through the registered aperture means in each set of lapped connector plate means to provide free vertical articulation and horizontal rigidity between adjacent sections;

each connector plate means having at least another portion of its upper surface concentric with said aperture means and tangent to the plane of said upper horizontal surface on the corresponding side rail;

said upper horizontal and arcuate surfaces providing a pair of parallel, continuous, gap-free tracksfor smoothly supporting a longitudinally movable discharge carriage of a bridge conveyor or the like throughout a substantial range of upwardly and downwardly articulated conditions of said section;

said belt compensating meansbeing effective to minimize fluctuations in belt tension resulting from variations in the degree of articulation between said sections. 7. In a portable belt conveyor, the combination of claim 6 in which said side rails comprise elongated, hollow, rectangular cross-section box members, said belt take-up means comprising piston and cylinder means within said box members engaging opposite ends of one of said belt-reversing pulleys, and said upper members for supporting said upper run are wholly contained between said box members below said tracks.

8. In an undergound mining system for moving mined material away from a mine face, a portable belt conveyor adapted to receive mined materials from an inbye bridge conveyor having a discharge carriage sup ported for longitudinal movement along said portable belt conveyor and adapted to dischargesaid mined material to an outbye extensible conveyor, said portable belt conveyor comprising:

a head end section;

a tail end section; belt drive means in one of said end sections;- a belt-reversing pulley in each of said end sections;- an endless belt trained about said" pulleys 'inu pper and lower runs extending alonga conveying'course between said end sections; v

belt take-up means in one of said end sections including means for selectively moving the belt-reversing pulley therein in'a direction parallel to said course to selectively vary the tension level in said belt;

belt compensating means in said head end sectionincluding a compensating roller engaged with the return run of the belt; means for guiding said compensating roller for movement in a'direction transverse to said return run, and biasing means urging said roller toward sald return run;

a series of intermediate frame sections arranged endto-end along said course between said end sections;

each of said intermediate frame sectionsincluding a pair of elongated side rails maintained in rigid, horizontally spaced relation parallel to said course by members extending between said side rails;

ground support means on said end and intermediate sections;

each of said intermediate frame sections having transverse supporting members for said upper and lower runs extending between said side rails; each of said side rails including an upper horizontal surface and having a longitudinal extension comprising at least one vertical connector plate at each end with its upper surface extending from the rail surface with a portion thereof in substantially coplanar relation therewith, each said connector plate of each side rail being in side-by-side lapped engagement with at least one similar connecting plate on an adjacent section;

each set of lapped connector plates having registered pivot apertures with securing elements extending therethrough providing free vertical articulation and horizontal rigidity between adjacent sections;

each said connector plate having another portion of its upper surface arcuate in form, concentric with said pivot aperture thereof and tangent to said upper horizontal surface on the corresponding side rail; said upper horizontal and arcuate surfaces providing a pair of parallel, continuous, gap-free tracks for smoothly supporting a longitudinally movable discharge carriage of a bridge conveyor or the like throughout a substantial range of upwardly and downwardly articulated conditions of said sections;

said belt compensating means being effective to minimize fluctuations in belt tension resulting from variations in the degree of articulation between said sections.

9. In a portable belt conveyor, the combination of claim 8 in which one of the connector plates in each said set of lapped connector plates has an outer vertical guide surface which is substantially coplanar with outer vertical guide surfaces on adjacent connected side rails providing a pair of parallel, continuous outer guides engageable with side portions of a longitudinally movable discharge carriage of a bridge conveyor to maintain the carriage aligned with said belt during movement along said side rails. V V

TO QTn aportabIe belt conveyor, a horizonta lly rigid and vertically flexible elongated frame extending along a conveying course and including:

a series of intermediate frame sections arranged endto-end along said course;

each of said intermediate frame sections including a pair of elongated side rails maintained in rigid, horizontally spaced relation parallel to said course by members extending be-tween said side rails;

each of said intermediate frame sections having trans-verse supporting member for said upper and lower runs extending between said side rails;

each of said side rails including an upper horizontal surface and having a longitudinal extension comprising at least one vertical connector plate at each end with its upper surface having a portion extending from the rail surface in coplanar relation therewith;

each said connector plate of each side rail being in side-by-side lapped engagement with at least one similar connect-ing plate on an adjacent section;

each set of lapped connector plates having registered pivot apertures with securing elements extending therethrough providing free vertical articulation and horizontal rigidity between adjacent sections; and

each said connector plate having a portion of its upper surface arcuate in form, concentric with said pivot aperture thereof and tangent to said upper horizontal surface on the corresponding side rails;

said upper horizontal and arcuate surfaces providing a pair of parallel, continuous, gap-free tracks throughout a substantial range of upwardly and downwardly articulated conditions of said sections for smoothly supporting a longitudinally movable discharge carriage of a bridge conveyor or the like.

11. In a portable belt conveyor for receiving the dis charge from a bridge conveyor:

head and tail end sections each having a beltreversing pulley;

belt drive means in one of said end sections for an endless belt extending between the pulleys;

a series of intermediate frame sections arranged endto-end along a conveying course between said end sections;

each of said intermediate frame sections including a pair of elongated side rails maintained in rigid, horizontally spaced relation parallel to said course by members extending between said side rails;

ground support members on said side rails;

each of said frame sections having upper and lower belt-supporting members extending transversely between said side railds for supporting upper and lower runs of a conveyor belt;

each of said side rails having an upper horizontal surface and having longitudinal extensions comprising vertical connector plate means at each end thereof, each of said connector plate means having aperture means therein and being in side-by-side lapped engagement with similar connected plate means on an adjacent section, the aperture means of the lapped connector plate means being in registration;

a horizontal pivot pin extending through the registered aperture means in each set of lapped connector plate means intermediate the upper and lower surfaces of the rail to provide free vertical articulation and horizontal rigidity between adjacent sections;

each connector plate means having an upper surface which is substantially a coplanar continuation of the upper rail surface with the upper portion of its free end being of arcuate form concentric with the aperture means and tangent to the plane of the upper surface of the connector plate means,

said upper surfaces of the rail and plate means providing a pair of parallel, continuous, gap-free tracks throughout a substantial range of upward and downward pivotal movements relative to each other.

a a a a a {$533 k UNITED STA'IES PATENT OFFICE CERTU ICEJE OF CQRRECTIQN Patent No. 3,762 ,532 Dated October 2 1972 Invcntor(s) Robert C. Nelson It is certified that: error appears in the above-identified patent and thet said Letters Patent are hereby corrected as shown below:

Col. 8, s. v

t l. 67, after "head" insert -end--. i Col. 9, l. 12 "member" should be -members-; l.' 37, "condition" should be --condit ions-; l. 63, 'after "intermediate" insert --frame-. 'Col. 10, l. 35, "comprising" should be -comprise- Col. 11, l. 3, after "intermediate" insert --frame-. Col. 12, l. l2,""rails" should be---rail-;

k l. 36, "r'ailds" shoilld be -rails---; l. 43,-,"conn'ected" should be -conneCtor-fl Signed and sealed this 19th day of March 197L (SEAL) Attest:

EDWARD M. FLETCHER, JR. C. MARSHALL DANN- Attesting Officer Commissioner of Patents 

1. In a portable belt conveyor for receiving the discharge from a bridge conveyor comprising: head and tail end sections each having a belt-reversing pulley; belt drive means in one of said end sections; a series of intermediate frame sections arranged end-to-end along a conveying course between said end sections; each of said intermediate frame sections including a pair of elongated side rails maintained in rigid, horizontally spaced relation parallel to said course by members extending between said side rails; ground support members on said side rails; each of said frame sections having upper and lower beltsupporting members extending transversely between said side rails for supporting upper and lower runs of a conveyor belt; each of said side rails having an upper horizontal surface and having longitudinal extensions comprising vertical connector plate means at each end thereof with its upper surface extending from the rail surface with a portion thereof in substantial coplanar relation, each of said connector plate means having aperture means therein and being in side-by-side lapped engament with similar connector plate means on an adjacent section, the aperture means of the lapped connector plate means being in registration; a horizontal pin extending through the registered aperture means in each set of lapped connector plate means to provide free vertical articulation and horizontal rigidity between adjacent sections; each connector plate means having at least another portion of its surface of arcuate form concentric with said aperture means and tangent to the plane of said upper horizontal surface on the corresponding side rail; said upper horizontal and arcuate surfaces providing a pair of parallel, continuous, gap-free tracks throughout a substantial range of upwardly and downwardly articulated conditions of said sections for smoothly supporting a longitudinally movable discharge carriage of a bridge conveyor or the like.
 2. In a portable belt conveyor, the combination of claim 1 in which said ground support members comprise ground-engaging skids carried by said side rails.
 3. In a portable belt conveyor, the combination of claim 2 in which a ground- and roof-engaging jack is swivelably supported on said head end section to enable said coNveyor to swing horizontally as a unit about said jack.
 4. In a portable belt conveyor, the combination of claim 1 in which each transverse pair of side rails are rigidly interconnected by transverse struts positioned between the upper and lower runs of a conveyor belt supported respectively on said upper and lower belt-supporting members.
 5. In an underground mining conveying system for moving mined materials away from a mine face, a portable belt conveyor adapted to receive mined material from an inbye bridge conveyor having a discharge carriage supported for longitudinal movement along said portable belt conveyor and adapted to discharge said mined material to an outbye conveyor, said portable belt conveyor comprising: a head section; a tail end section; a belt-reversing pulley in each of said end sections; an endless belt trained between said pulleys in upper and lower runs and extending along a conveying course between said end sections; belt drive means in one of said end sections; a series of intermediate frame sections arranged end-to-end along said course between said end sections; each of said intermediate frame sections including a pair of elongated side rails maintained in rigid, horizontally spaced relation parallel to said course by members extending between said side rails; ground support member on said side rails; each of said intermediate frame sections having transverse supporting members for said upper and lower runs extending between said side rails; each of said side rails including an upper horizontal surface and having a longitudinal extension comprising at least one vertical connector plate at each end with its upper surface extending from the rail surface with a portion thereof in substantial coplanar relation; each said connector plate of each side rail being in side-by-side lapped engagement with at least one similar connecting plate on an adjacent section; each set of lapped connector plates having registered pivot apertures with securing elements extending therethrough providing free vertical articulation and horizontal rigidity between adjacent sections; each said connector plate having another portion of the upper surface of arcuate form concentric with said pivot aperture thereof and tangent to the plane of said upper horizontal surface on the corresponding side rail; said upper horizontal and arcuate surfaces providing a pair of parallel, continuous, gap-free tracks throughout a substantial range of upwardly and downwardly articulated condition of said sections for smoothly supporting a longitudinally movable discharge car-riage of a bridge conveyor or the like.
 6. In a portable belt conveyor for receiving the discharge from a bridge conveyor comprising: head and tail end sections each having a belt-reversing pulley; belt take-up means in one of said sections including means for selectively moving the belt-reversing pulley therein in a direction parallel to said course to selectively vary the tension level in a belt; belt compensating means in said head end section in-cluding a compensating roller engageable with the return run of a belt, means for guiding said compensating roller for movement in a direction transverse to said return run, and biasing means urging said roller toward said return run; belt drive means in one of said sections; a series of intermediate frame sections arranged end-to-end along a course between said end sections; each of said intermediate frame sections including a pair of elongated side rails maintained in rigid, horizontally spaced relation parallel to said course by members extending between said side rails; ground support means on said end and intermediate sections; each of said intermediate frame sections having upper and lower members extending transversely between said side rails for supporting upper and lower runs of a conveyor belt; each of said side rails having an upper horizontal suRface and having longitudinal extensions comprising vertical connector plate means at each end thereof with its upper surface extending from the rail surface with a portion thereof in substantial coplanar relation, each of said connector plate means having aperture means therein and being in side-by-side lapped engagement with similar connector plate means on an adjacent section, the aperture means of the lapped connector plate means being in registration; a horizontal pivot pin extending through the registered aperture means in each set of lapped connector plate means to provide free vertical articulation and horizontal rigidity between adjacent sections; each connector plate means having at least another portion of its upper surface concentric with said aperture means and tangent to the plane of said upper horizontal surface on the corresponding side rail; said upper horizontal and arcuate surfaces providing a pair of parallel, continuous, gap-free tracks for smoothly supporting a longitudinally movable discharge carriage of a bridge conveyor or the like throughout a substantial range of upwardly and downwardly articulated conditions of said section; said belt compensating means being effective to mini-mize fluctuations in belt tension resulting from variations in the degree of articulation between said sections.
 7. In a portable belt conveyor, the combination of claim 6 in which said side rails comprise elongated, hollow, rectangular cross-section box members, said belt take-up means comprising piston and cylinder means within said box members engaging opposite ends of one of said belt-reversing pulleys, and said upper members for supporting said upper run are wholly contained between said box members below said tracks.
 8. In an undergound mining system for moving mined material away from a mine face, a portable belt conveyor adapted to receive mined materials from an inbye bridge conveyor having a discharge carriage supported for longitudinal movement along said portable belt conveyor and adapted to discharge said mined material to an outbye extensible conveyor, said portable belt conveyor comprising: a head end section; a tail end section; belt drive means in one of said end sections; a belt-reversing pulley in each of said end sections; an endless belt trained about said pulleys in upper and lower runs extending along a conveying course between said end sections; belt take-up means in one of said end sections including means for selectively moving the belt-reversing pulley therein in a direction parallel to said course to selectively vary the tension level in said belt; belt compensating means in said head end section including a compensating roller engaged with the return run of the belt; means for guiding said compensating roller for movement in a direction transverse to said return run, and biasing means urging said roller toward saId return run; a series of intermediate frame sections arranged end-to-end along said course between said end sections; each of said intermediate frame sections including a pair of elongated side rails maintained in rigid, horizontally spaced relation parallel to said course by members extending between said side rails; ground support means on said end and intermediate sections; each of said intermediate frame sections having transverse supporting members for said upper and lower runs extending between said side rails; each of said side rails including an upper horizontal surface and having a longitudinal extension comprising at least one vertical connector plate at each end with its upper surface extending from the rail surface with a portion thereof in substantially coplanar relation therewith, each said connector plate of each side rail being in side-by-side lapped engagement with at least one similar connecting plate on an adjacent section; each set of lapped connector plates having registered pivot apertures with securing elements extending therethrough providing free vertical articulation and horizontal rigidity between adjacent sections; each said connector plate having another portion of its upper surface arcuate in form, concentric with said pivot aperture thereof and tangent to said upper horizontal surface on the corresponding side rail; said upper horizontal and arcuate surfaces providing a pair of parallel, continuous, gap-free tracks for smoothly supporting a longitudinally movable discharge carriage of a bridge conveyor or the like throughout a substantial range of upwardly and downwardly articulated conditions of said sections; said belt compensating means being effective to minimize fluctuations in belt tension resulting from variations in the degree of articulation between said sections.
 9. In a portable belt conveyor, the combination of claim 8 in which one of the connector plates in each said set of lapped connector plates has an outer vertical guide surface which is substantially coplanar with outer vertical guide surfaces on adjacent connected side rails providing a pair of parallel, continuous outer guides engageable with side portions of a longitudinally movable discharge carriage of a bridge conveyor to maintain the carriage aligned with said belt during movement along said side rails.
 10. In a portable belt conveyor, a hori-zontally rigid and vertically flexible elongated frame extending along a conveying course and including: a series of intermediate frame sections arranged end-to-end along said course; each of said intermediate frame sections including a pair of elongated side rails maintained in rigid, horizontally spaced relation parallel to said course by members extending be-tween said side rails; each of said intermediate frame sections having trans-verse supporting member for said upper and lower runs extending between said side rails; each of said side rails including an upper horizontal surface and having a longitudinal extension comprising at least one vertical connector plate at each end with its upper surface having a portion extending from the rail surface in coplanar relation therewith; each said connector plate of each side rail being in side-by-side lapped engagement with at least one similar connect-ing plate on an adjacent section; each set of lapped connector plates having registered pivot apertures with securing elements extending therethrough providing free vertical articulation and horizontal rigidity between adjacent sections; and each said connector plate having a portion of its upper surface arcuate in form, concentric with said pivot aperture thereof and tangent to said upper horizontal surface on the corresponding side radil; said upper horizontal and arcuate surfaces providing a pair of parallel, continuous, gap-free tracks throughout a substantial range of upwardly and downwardly articulated conditions of said sections for smoothly supporting a longitudinally movable discharge carriage of a bridge conveyor or the like.
 11. In a portable belt conveyor for receiving the discharge from a bridge conveyor: head and tail end sections each having a belt-reversing pulley; belt drive means in one of said end sections for an endless belt extending between the pulleys; a series of intermediate frame sections arranged end-to-end along a conveying course between said end sections; each of said intermediate frame sections including a pair of elongated side rails maintained in rigid, horizontally spaced relation parallel to said course by members extending between said side rails; ground support members on said side rails; each of said frame sections having upper and lower belt-supporting members extending transversely between said side railds for supporting upper and lower runs of a conveyor belt; each of said side rails having an upper horizontal surface and having longitudinal extensions comprising vertical connector plate means at each end thereof, each of Said connector plate means having aperture means therein and being in side-by-side lapped engagement with similar connected plate means on an adjacent section, the aperture means of the lapped connector plate means being in registration; a horizontal pivot pin extending through the registered aperture means in each set of lapped connector plate means intermediate the upper and lower surfaces of the rail to provide free vertical articulation and horizontal rigidity between adjacent sections; each connector plate means having an upper surface which is substantially a coplanar continuation of the upper rail surface with the upper portion of its free end being of arcuate form concentric with the aperture means and tangent to the plane of the upper surface of the connector plate means, said upper surfaces of the rail and plate means providing a pair of parallel, continuous, gap-free tracks throughout a substantial range of upward and downward pivotal movements relative to each other. 